The metabolic clearance and production rates of human growth hormone in patients with juvenile diabetes mellitus and in prediabetic subjects will be examined. The contribution of splanchnic clearance to the overall metabolic clearance of HGH will be investigated. In vivo bidirectional transport of radiolabeled HGH in the meternal fetal complex of the pregnant Macaca mulatta and the fetal hormonal response to changes in the fetal and maternal environment will be investigated. The in utero fetal plasma HGH concentrations and the metabolism of HGH in early neonatal life will be examined.